Understanding Flyback Transformer Pin

Monitor and Television flyback transformers have some common design except only on the internal capacitor. Monitor flyback transformer have the internal capacitor around 2.7 nanofarad to 6 nanofarad to improve the picture quality. Without the internal capacitor the display will curve or slightly out of shape especially at both the right and left hand side of the dispay. Generally flyback transformers will have about ten pins at the bottom of the flyback. Each pin have a purpose or function as part of a complete circuit. The common pins that you can find in monitor flyback are: B+, Horizonatl collector pulse, ABL
(automatic blanking limiter), GROUND, G1, AFC (automatic frequency control), VCC, HEATER (to filament) and X-RAY PROTECT.
B+ and horizontal collector pulse forms one winding which we call it as flyback primary winding and only can be accurately check using a flyback tester such as the Dick Smith Lopt tester.  Normal multimeter can't check this kind of problem. This is the most important winding compares to others and easily will develop a short circuit when B+ line or Horizontal output transistor (HOT) have problem. Sometimes a shorted internal capacitor in the flyback transformer may cause the primary winding to burn internally and became bulge.
Next pins are the ground, G1, and AFC winding. AFC stand for automatic frequency control and it send signal from the flyback to the horizontal oscillator ic to lock or synchronize the frequency of the monitor. If this afc line have problems the picture will move either to the far left or far right. There is no way you can adjust the picture to the center even with the OSD Control. The purpose of G1 is to pull the electron generated from the cathode and channel it to G2 which is the screen voltage. G1 normally is a negative voltage. If there is a missing G1 voltage (zero voltage) to the picture tube the monitor display will become very bright with flyback lines (diagonal lines) across the screen and sometimes the monitor will goes into shutdown mode.

ABL stand for automatic blanking limiter- I refer it as a contrast circuit. Why? because whenever there is a contrast problem i will search for this pin and begin to trace from there. Normally a resistor increased in resistance and a shorted ceramic capacitor caused the display to become dim and you think it might be the fault of a bad picture tube. Heater pin nowadays hardly found in monitor flyback because the crt heater voltage now is derived directly from the switch mode power supply. Heater pin still can be found in television flyback transformer. If the anode voltage is too high (more than 28-30 kv), x-ray protect pin will send a signal to horizontal oscillator ic to disable the horizontal drive waveform. Without the horizontal drive waveform the high voltage will collapsed and protect the user from excessive x-ray generated by the abnormal high voltage. The flyback transformer will also generate high pulse ac which later convert to dc thru a ultra fast recovery diode, The dc voltage then are supply to various circuit such as the vertical circuit. If you truly understand how a flyback transformer work and the functions of each pin, troubleshooting  monitor or tv will be much easier and faster. If you want to know more details of tv and monitor flyback transformer you may get a CD from HRDIEMEN spain.